1. Field of the Invention
The present disclosure relates to generally to thermal management systems, and more particularly to cooling system such as for transferring heat.
2. Description of Related Art
Applications such as high power lasers, electronics, power generators and conversion equipment all generate waste heat and require cooling. In many of these applications the cooling heat flux is high or a suitable heat sink is not adjacent to the heat losses. In these cases a thermal loop maybe used that acquires heat where it is dissipated and transports that heat to a heat exchanger at the heat sink. Typically, such cooling systems can add significantly to the overall system mass, size, and average power consumption. Most commonly the coolant is a single phase fluid (gas or liquid) that works by sensible heating and cooling i.e., increases in temperature as it acquires heat at the heat load and decreases in temperature in the heat exchanger at the heat sink.
In some systems, for example LASERs, microwaves and other Directed Energy Weapons (DEW), the heat losses may be very intermittent with rest periods much longer than the power burst. Thermal systems that transport and reject these discontinuous heat loads as they occur will be unnecessarily large and heavy because they must be designed for peak energy conditions. If a cooling system includes Thermal Energy Storage (TES) the peak heat rejection rate can be reduced and the heat sink heat exchangers can be smaller and lighter. The utilization of thermal energy storage can reduce the heat rejection rate from the short duration peak value to a much lower rate of heat rejection at the heat sink. In the ideal case with thermal storage, heat is continuously rejected to the heat sink at the time averaged heat load over the duty cycle. Therefore, thermal management systems that can store as well as reject heat from non-steady thermal loads can be smaller and lighter than systems that reject heat as it is generated.
Conventional single phase thermal management systems without thermal storage have generally been considered satisfactory for their intended purpose. However, there is still a need in the art for improved thermal management systems. The present disclosure presents a thermal management system for intermittent heat loads that will be smaller, lighter and require less power than conventional approaches by utilizing thermal storage integrated into a two-phase loop.